Assemblies comprising fastener with ergonomically balanced removal to insertion ratio

ABSTRACT

Assemblies comprising a fastener, which has engagement springs in opposite sides of the fastener. Each engagement spring has an engagement region comprising a hindrance portion, which increases considerably the removal to insertion force ratio as compared to such ratio in the absence of the hindrance portion, thus permitting very easy insertion with considerably more difficult removal of the fastener from the slot of a panel, which provides an efficient ergonomically balanced removal to insertion force ratio. The hindrance portion comprises ripples or other hindrance elements of unexpectedly minute dimensions for providing this efficient ergonomic force balance.

RELATED APPLICATIONS

This application is a Divisional of Ser. No. 10/164,963 filed Jun. 7,2002 now U.S. Pat. No. 6,718,599. This application claims priority ofprovisional patent applications 60/301,364, filed Jun. 25, 2001,60/327,815, filed Oct. 9, 2001, and 60/353,515, filed Feb. 1, 2002, allthree of which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

This invention relates to spring fasteners characterized by a structurehaving a cavity in which an extension or rib of a first part, such as aplastic panel for example, may be engaged, and they are also suitable tobe engaged reversibly in a slot of second part, such as a metal sheet orthe frame of a car for example. The invention also pertains an assemblyof the first and the second part as connected to each other through thefastener, as well as vehicles comprising such assemblies.

BACKGROUND OF THE INVENTION

A number of fasteners have been used in the past for securing one objecton another object, as for example, securing an article such as forexample a plastic sheet on a metal or other rigid plastic sheet.However, the fasteners of the type, which are improved by the advancesof the present invention, and being used presently, have a rather lowratio of insertion force to removal force. In other words, they requireconsiderable force to be inserted into a slot in order to provideadequate removal resistance in order to be removed from the slot. Thisis ergonomically inferior performance, and the operators may suffermiscellaneous ailments, while productivity is also considerablyundermined.

Examples of conventional fasteners are disclosed in U.S. Pat. No.5,987,714 (Smith); U.S. Pat. No. 5,887,319 (Smith); U.S. Pat. No.5,542,158 (Gronau et al.); U.S. Pat. No. 5,422,789 (Fisher et al.), U.S.Pat. No. 5,373,611 (Murata); U.S. Pat. No. 5,314,280 (Gagliardi); U.S.Pat. No. 5,095,592 (Doerfling); U.S. Pat. No. 4,792,475 (Bien U.S. Pat.No. 4,683,622 (Ohelke); U.S. Pat. No. 4,609,170 (Schnabl); U.S. Pat. No.4,245,652 (Kelly et al.); U.S. Pat. No. 3,864,789 (Leitner); U.S. Pat.No. 3,673,643 (Kindell); U.S. Pat. No. 3,525,129 (Holton), U.S. Pat. No.2,825,948 (Parkin); U.S. Pat. No. 2,607,971 (Bedford, Jr.); U.S. Pat.No. 2,542,883 (Tinnerman); U.S. Pat. No. 2,329,688 (Bedford, Jr.); U.S.Pat. No. 2,322,656 (Murphy), among others.

U.S. Pat. No. 5,919,019 (Fisher) provides fasteners which can only bepermanently installed into a slot; they can only be inserted but notextracted without damage to parts of the fastener. The major engagementis performed by spring strips, while frictional portions of the fastenerpass through the slot with at most slight compression, and immediatelyafter the insertion of the fastener they are located in slightly spacedor barely contacting relation with the edges of the slot. They are onlyactivated for engagement after the insertion of a bolt into a hole atthe base plate. Thus, the profound effect of the increased removal toinsertion ratio (explained in detail hereinbelow) is not recognized,mentioned, or implied. Thus, the intentionally provided distance of thefrictional portions away from the edges of the slot by Fisher, duringinsertion and before use of the bolt, teaches actually away from theinstant invention, which recognizes and takes full advantage of theincreased removal to insertion ratio by an engagement region having ahindrance portion. As a matter of fact, if the engagement surfaces ofthe instant invention were located in slightly spaced or barelycontacting relation with the edges of the slot, no engagement at allwould take place upon insertion of the fastener of this invention intothe slot.

U.S. Pat. No. 6,141,837 (Wisniewski) describes a spring fastenercomprising bulbous and outwardly projecting portions, which assist inpreventing withdrawal of the clip and associated molding from anaperture of a vehicle frame. However, “bulbous projections” arenecessarily voluminous, take most of the space between the “reversebents”, and unless they are manufactured within tight tolerances withregard to the thickness of the frame, the “base plates” do not sit onthe frame (see also the Figures), rendering the structure unstable.

U.S. Pat. No. 6,203,240 B1 (Hironaka et al.), U.S. Pat. No. 5,129,768(Hoyle et al.), U.S. Pat. No. 5,092,550 (Bettini), U.S. Pat. No.4,981,310 (Belissaire), U.S. Pat. No. 4,712,341 (Harris, Jr. et al.),U.S. Pat. No. 4,595,325 (Moran et al.), U.S. Pat. No. 4,431,355(Junemann), U.S. Pat. No. 4,133,246 (Small), and U.S. Pat. No. 2,424,757(F. Klump, Jr.) are directed to plastic or metal fasteners which aredesigned to be just inserted into the slot of a panel, but not extractedwithout damage to the fastener (if such extraction would be attemptedfrom the front side; the side from which the fastener is inserted intothe panel, since the back part of the panel is not reachable in thecases, wherein such types of fasteners are used).

SUMMARY OF THE INVENTION

As aforementioned, this invention relates to spring fastenerscharacterized by a structure having a cavity in which the rib of a firstpart, such as a plastic panel for example, may be engaged, and they arealso suitable to be engaged reversibly in a slot of second part, such asa metal sheet or the frame of a car for example. The invention alsopertains an assembly of the first and the second part as connected toeach other through the fastener, as well as vehicles comprising suchassemblies.

More particularly, the invention pertains a spring fastener comprising afirst side and a second side opposite the first side, the first sideconnected to the second side thereby forming a U-shaped structure havinga cavity between the first side and the second side, a bottom portionwherein the first side and the second side are connected, and a topportion, the first side comprising first barbs having first front ends,and a first engagement spring, the first engagement spring connected tothe first side in the vicinity of the bottom portion, the second sidecomprising second barbs second front ends, and a second engagementspring, the second engagement spring connected to the second side in thevicinity of the bottom portion, each of the first and second engagementsprings having a recess and a free end in the vicinity of the topportion, each spring also comprising a peak and an engagement regionwith a hindrance portion between the recess and the peak, the hindranceportion providing increased removal force, when the fastener is pulledby a rib of a first part engaged to the first and second barbs, afterthe fastener has been inserted into a slot of a second part, the slothaving a slot width and edges on which edges the engagement region isengaged, the increased removal force being due to the hindrance portion,and wherein the fastener can be extracted when pulled by the rib withoutdamage to said fastener.

This invention further pertains an assembly comprising:

-   -   a spring fastener comprising a first side and a second side        opposite the first side, the first side connected to the second        side thereby forming a U-shaped structure having a cavity        between the first side and the second side, a bottom portion        wherein the first side and the second side are connected, and a        top portion, the first side comprising first barbs having first        front ends, and a first engagement spring, the first engagement        spring connected to the first side in the vicinity of the bottom        portion, the second side comprising second barbs second front        ends, and a second engagement spring, the second engagement        spring connected to the second side in the vicinity of the        bottom portion, each of the first and second engagement springs        having a recess and a free end in the vicinity of the top        portion, each spring also comprising a peak and an engagement        region with a hindrance portion between the recess and the peak;    -   a first part comprising a rib inserted into the cavity of the        spring fastener and engaged to the first and second barbs; and    -   a second part comprising a slot, the slot having a width and        edges, the fastener being disposed in the slot in a manner that        the edges of said slot are engaged to the engagement regions of        the spring fastener;    -   with the requirement that by pulling the rib, the fastener is        extracted from the slot without damage to the fastener, and with        a higher force than a force required in the absence of the        hindrance portion.

In addition, this invention is related to a vehicle which comprises anassembly, the assembly comprising vehicle comprising an assembly, theassembly comprising:

-   -   a spring fastener comprising a first side and a second side        opposite the first side, the first side connected to the second        side thereby forming a U-shaped structure having a cavity        between the first side and the second side, a bottom portion        wherein the first side and the second side are connected, and a        top portion, the first side comprising first barbs having first        front ends, and a first engagement spring, the first engagement        spring connected to the first side in the vicinity of the bottom        portion, the second side comprising second barbs second front        ends, and a second engagement spring, the second engagement        spring connected to the second side in the vicinity of the        bottom portion, each of the first and second engagement springs        having a recess and a free end in the vicinity of the top        portion, each spring also comprising a peak and an engagement        region with a hindrance portion between the recess and the peak;    -   a first part comprising a rib inserted into the cavity of the        spring fastener and engaged to the first and second barbs; and    -   a second part comprising a slot, the slot having a width and        edges, the fastener being disposed in the slot in a manner that        the edges of said slot are engaged to the engagement regions of        the spring fastener;    -   with the requirement that by pulling the rib, the fastener is        extracted from the slot without damage to the fastener, and with        a higher force than a force required in the absence of the        hindrance portion.

According to this invention, and particularly for ergonomic purposescombined with practical aspects, it is highly preferable that the forceto insert the rib of the first part into the cavity of the springfastener should be less than 40 lbs, preferably less than 15 lbs, andeven more preferably less that 10 lbs; the force to insert the springfastener into the slot should be less that 30 lbs, preferably less than15 lbs, and even more preferably less than 10 lbs; and the force toextract the spring fastener from the slot should be in the range of30-100 lbs, and preferably in the range of 50-70 lbs.

To achieve the above results, in a preferred embodiment of thisinvention, the hindrance portion comprises one structure selected fromripple, side rib, upward solid bent extension parallel to the peak andthe recess, knurled region, bent teeth, each having a depth, and acombination thereof.

It is preferable that the depth of the ripple, the side rib, the upwardsolid bent extension which is parallel to the peak, the knurled region,and the bent teeth is smaller than 0.2 mm.

It is further preferable that each ripple is in the form of adepression, the depression having a deepest part, a front side, a backside and a width, and the hindrance portion has a surface, comprises notmore than three ripples, and wherein the depth of each ripple is thedistance between the surface of the hindrance portion and the deepestpart of the respective ripple.

It is more preferable that the hindrance portion comprises not more thantwo ripples, and even more preferable one ripple.

For better performance, the ripple width is larger than the depth of theripple, and preferably the ripple width is at least twice the size ofthe depth of the ripple.

The ripple width is preferably in the range of 0.1 to 0.5 mm and theripple depth is in the range of 0.01 to 0.1 mm.

In a preferred embodiment, the back side of the ripple has a slope inthe range of 15 to 30 degrees with regard to the general plane of thehindrance portion, and it is also preferable that the front side has ahigher slope than the back side.

In the case that the hindrance portion comprises a single ripple, it ishighly preferable that the ripple has only a back side, andsubstantially lacks a front side. It is also highly preferable that theback side has the form of a curvature with a gradually decreasing slope.For example, the gradually decreasing slope may have the shape of an arcin the range of 50-70 degrees with a radius in the range of 0.03-0.05mm.

The barbs are preferably selected from a group consisting essentiallyof:

-   -   first barbs being outer barbs and second barbs being inner        barbs;    -   first barbs being outside outer barbs and second barbs being        inside outer barbs; and    -   first barbs being inner barbs and second barbs being inner        barbs.

It is preferable that the barbs are cut from their respective side, areflexible, and bent in the vicinity of their respective front end asdescribed for example in U.S. Pat. No. 6,279,207 B1, which isincorporated herein by reference, and more particularly in FIG. 1 ofsaid patent, with an angle of bent in the range of 5-25 degrees.

The barbs are considered to be flexible if they do not cause the widthW3 (FIG. 1A) to increase more than 30%, preferably 20%, and morepreferably 10%, when the rib 46 is inserted into the cavity 19 of thefastener 10 (FIG. 4A), and provided that the first object 46 isadequately hard to hinder the barbs 36 from substantially digging intoit.

Regarding the outside outer barbs, it is preferable that their frontpoints are at a distance from the second side smaller than the thicknessof the material from which the spring fastener was made. This is toavoid interconnection of the fasteners, when said fasteners are storedin bulk.

The barbs may have variable width along their length, or they may havesubstantially the same width along their length. Further, the frontpoints of the barbs may be toothed.

It is also preferable that the fastener has a width in the vicinity ofthe top portion of the fastener which is at least 60%, and morepreferably at least 70%, as wide as the slot width.

With respect to the engagement region it is preferable that it is atleast partially wider than the rest of the engagement spring.

The spring fasteners of the instant invention may have two engagementsprings at the edges of each side instead of one engagement spring insubstantially the middle portion of each side.

The spring fastener may further comprise additional lower barbs pointinginwardly and originating form the vicinity of the bottom portions of thefirst side and the second side of the fastener. In another embodiment,each side of the spring fastener has only one upper barb and one lowerbarb, the upper barb of one side facing the lower barb of the other sideand vice versa. In still another embodiment, the fastener may furthercomprise a relief opening in the vicinity of the bottom of the springfastener.

The spring fastener of the instant invention may further comprise amolded elastic body under the top portion of said spring fastener. Sucharrangements are disclosed in U.S. Pat. No. 6,353,981 B1, which isincorporated herein by reference.

In another embodiment, the spring fastener of the instant invention mayfurther comprise:

an elastic body comprised of at least a gasket, the gasket extendingaway from the closed cavity in the vicinity of the top portion of thefastener and enclosing at least partially the cavity; and

a casing surrounding at least partially the spring fastener under thetop portion, except at least the engagement section of each engagementspring, the casing also at least partially surrounding the cavity andsuch portion of the elastic body which at least partially encloses thecavity;

wherein the casing has lower ultimate elongation, higher Shore hardness,and higher shear strength than the elastic body.

Such arrangements are disclosed in U.S. Pat. No. 6,381,811 B2, which isincorporated herein by reference

According to the present invention, any embodiments of fastenersdescribed above and their equivalents may be used in any assembly inwhich the first part and the second part are connected with thefastener, as well as in any vehicle comprising such an assembly or sucha fastener or its equivalents.

DESCRIPTION OF THE DRAWING

The reader's understanding of practical implementation of preferredembodiments of the invention will be enhanced by reference to thefollowing detailed description taken in conjunction with perusal of thedrawing figures, wherein:

FIG. 1 illustrates a perspective view of a spring fastener according toa preferred embodiment of the present invention, wherein the hindranceportion comprises a single-sided ripple and bent barbs.

FIG. 1A shows a side view of the spring fastener of FIG. 1.

FIG. 2 illustrates a perspective view of a spring fastener according toanother preferred embodiment of the present invention, wherein thehindrance portion comprises one two-sided ripple and bent barbs.

FIG. 3A illustrates a fragmental cross-sectional view of an engagementspring, wherein the hindrance portion comprises a single-sided ripple.

FIG. 3B illustrates a fragmental cross-sectional view of an engagementspring, wherein the hindrance portion comprises one two-sided ripple.

FIG. 3C illustrates a fragmental cross-sectional view of an engagementspring, wherein the hindrance portion comprises two two-sided ripples.

FIG. 3D illustrates a fragmental cross-sectional view of an engagementspring, wherein the hindrance portion comprises three two-sided ripples.

FIG. 4 illustrates two parts, which can be connected with the fasteneraccording to the present invention.

FIG. 4A illustrates the side view of the fastener of FIG. 1 and a crosssection of the rib of a first part, such as a panel for example,inserted into the cavity of the fastener.

FIG. 4B illustrates the same elements shown in FIG. 4A after insertionof the fastener into the slot of a second part, such as the frame of anautomobile for example.

FIG. 4C illustrates a fragmental cross section of the second part ofFIG. 4B and the edges of the slot in relation with the engagementregions of the engagement springs of the fastener.

FIG. 5 illustrates a detailed diagram of a ripple in the hindranceportion according to preferred embodiments of the instant invention.

FIG. 5A illustrates a detailed diagram of a single-sided ripple having aback side in the form of a curvature in the hindrance portion accordingto a highly preferred embodiment of the instant invention.

FIG. 6 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises outer and inner barbs, as well as relief portions in thevicinity of the bottom of the fastener.

FIG. 6A illustrates a side view of the fastener of FIG. 6 after finalformation.

FIG. 7 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises outside outer barbs on the first side and inside outer barbson the second side.

FIG. 8 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises only inner barbs.

FIG. 9 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises upper and lower outer and inner barbs.

FIG. 10 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises two engagement springs per side of the fastener, and only oneupper and one lower barb per side.

FIG. 11 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the barbs haveuniform width along their length.

FIG. 12 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the barbs haveuniform width along their length, and they are toothed at their frontends.

FIG. 13 illustrates a cross-sectional view of the middle portion of aspring fastener, according to another embodiment of the instantinvention, wherein a molded elastic body 54 is disposed at least underthe top portion of said spring fastener.

FIG. 14 is a perspective view of a fastener, according to still anotherembodiment of the instant invention, wherein the lower portion of thefastener is covered by a casing, while an elastic body is disposed inthe vicinity of the top portion and encloses the cavity, at leastpartially.

DETAILED DESCRIPTION OF THE INVENTION

As aforementioned, this invention relates to spring fastenerscharacterized by a structure having a cavity in which the rib of a firstpart, such as a plastic panel for example, may be engaged, and they arealso suitable to be engaged reversibly in a slot of second part, such asa metal sheet or the frame of a car for example. The invention alsopertains an assembly of the first and the second part as connected toeach other through the fastener, as well as vehicles comprising suchassemblies.

More particularly, as better shown in FIGS. 1 and 1A, the inventionpertains a spring fastener 10 comprising a first side 12 and a secondside 14 opposite the first side 12. The first side 12 is connected tothe second side 14 forming a U-shaped structure which has a cavity 19between the first side 12 and the second side 14. The fastener 10 alsohas a bottom portion 16, wherein the first side 12 and the second side14 are connected. It further has a top portion 18 a and 18 b(collectively 18).

In all cases, numerals referring to the first side 12 contain the letter“a”, while numerals referring the second side 14 contain the letter “b”.The same numerals without the letters “a” or “b”, refer collectively tothe respective elements of both sides.

The first side 12 comprises first barbs 36 a, which in this case areouter barbs, since they are disposed in an outer portion of the firstside 12. The barbs 36 a have first front ends 38 a. In this particularcase the first barbs 36 a are bent inwardly in the vicinity of the frontends 38 a, as it will be explained in more detail at a later point.

The first side 12 also comprises a first engagement spring 20 a, whichis connected to the first side 12 in the vicinity of the bottom portion16.

The second side 14 comprises second barbs 36 b, which in this case areinner barbs, since they are disposed in an inner portion of the secondside 14. The second barbs have second front ends 38 b. In thisparticular case the first barbs 36 b are also bent inwardly in thevicinity of the front ends 38 b, as it will be explained in more detailat a later point.

The second side 14 comprises a second engagement spring 20 b, which isconnected to the second side 14, also in the vicinity of the bottomportion.

Each of the first and second engagement springs 20 a and 20 b have afirst and second recess, 24 a and 24 b, respectively, and a first andsecond free end, 22 a and 22 b, respectively, in the vicinity of the topportion 18 (18 a and 18 b, respectively). Each spring also comprises afirst and a second peak, 26 a and 26 b, respectively, and a first andsecond engagement region, 28 a and 28 b, respectively, with a first andsecond hindrance portion, 29 a and 29 b, respectively, between therecesses 24 and the peaks 26.

The hindrance portions providing increased removal force, when thefastener 10 is pulled by a rib or extension 46 (FIG. 4B) of a first part44 (FIG. 4) engaged to the first and second barbs, 36 a and 36 b,respectively, after the fastener 10 has been inserted into a slot 50 ofa second part 48 (FIG. 4), the slot 50 having a slot width W2 (FIGS. 4and 4C) and edges 51 (FIG. 4C) on which edges the engagement regions 28a and 28 b are engaged. The increased removal force is due to thehindrance portions 29 a and 29 b (FIG. 4C), which in this particularcase comprise single ripples with only back sides 34, as it will beexplained at a later point in more detail. According to this invention,the engagement portions 28 a and 28 b and the hindrance regions 29 a and29 b are required to be such that the fastener 10 can be extracted fromthe slot 50 when pulled by the rib 46 without damage to said fastener10, and with a higher force than a force required in the absence of thehindrance portions 29 a and 29 b.

This invention further pertains an assembly 11, as better shown in FIG.4B, comprising a spring fastener as described above or in theembodiments presented hereinbelow; a first part 44 (FIG. 4) comprising arib 46 (FIG. 4A) inserted into the cavity 19 of the spring fastener 10and engaged to the first and second barbs 36 a and 36 b; and a secondpart 48 (FIGS. 4 and 4B) comprising a slot 50, which slot 50 has a widthW2 and edges 51 (FIG. 4C), so that the edges 51 of said slot are engagedto the engagement regions 28 a and 28 b of the spring fastener 10. Inthis case also, the requirement exists that by pulling the rib 46, thefastener 10 is extracted from the slot 50 without damage to the fastener10, and with a higher force than a force required in the absence of thehindrance portions 29 a and 29 b.

In addition, this invention is related to a vehicle which comprises anassembly 11, as described above.

In operation of the above embodiments, the spring fastener 10 of thepresent invention is intended to connect a first part, such as a panel44 for example, which panel may have a rib 46, with a second part, suchas a frame 48 of a car for example, having a slot 50, as illustrated inFIG. 4.

The rib 46 of the panel 44 is preferably first inserted into the cavity19 of the fastener 10 (see FIG. 4A), where, it is secured by barbs 36 aand 36 b. Then, the fastener 10, which has been secured on the extension46 of the panel 44, is inserted into the slot 50 of the frame 48, asbetter shown in FIG. 4B.

In this manner, the first part, exemplified by panel 44, has beenconnected on the second part, exemplified by frame 48, through thefastener 10 of the instant invention.

In most practical applications, the length Le (see FIG. 4A) of theengagement regions 28 is not higher than 2-4 mm, while the thicknessT_(f) of the frame 48 (see FIG. 4B) may vary in most occasions in therange of 0.5 to 2 mm. This fact makes it rather difficult to form largehindrance portions. Thus, The “bulbous projections” suggested by U.S.Pat. No. 6,141,837 (Wisniewski) are necessarily too bulky andvoluminous, take most of the space between the “reverse bents”(engagement regions between the peak and the recess in the case of theinstant invention), and unless they are manufactured within tighttolerances with regard to the thickness of the frame (which in practicemay vary considerably), the “base plates” (top portions in the case ofthe present invention) do not sit on the frame (see also Wisniewski'sFigures), rendering the structure considerably unstable.

According to this invention, and particularly for ergonomic purposescombined with practical aspects, it is highly preferable that the forceto insert the rib of the first part into the cavity of the springfastener should be less than 40 lbs, preferably less than 15 lbs, andeven more preferably less that 10 lbs; the force to insert the springfastener into the slot should be less that 30 lbs, preferably less than15 lbs, and even more preferably less than 10 lbs; and the force toextract the spring fastener from the slot should be in the range of30-100 lbs, and preferably in the range of 50-70 lbs.

It was unexpectedly found by the inventors that in order to achieve theabove results, the hindrance portions should comprise rather minuteelements, and not the huge structural components disclosed in the art.Such huge structural components render respective fasteners to beirreversibly inserted into slots. Any attempt to extract these fastenersfrom the side of the panel that they were, inserted would result indestruction of the fasteners.

According to this invention, the hindrance portions 29 a and 29 b maycomprise minute elements, such as ripples, upward solid bent extensionsparallel to the peaks and the recesses, knurled regions, bent teeth,each having a depth, the depth of which does not exceed preferably 0.2mm, and more preferably 0.1 mm. Any person of ordinary skill in the artwould not expect that elements having such minute depths would have suchgreat impact in force balances as the aforementioned ones.

The depth for any element is substantially defined in the same manner asdefined at a later point for the ripples.

Although this invention includes any structure which satisfies theclaims, such as for example upward solid bent extensions parallel to thepeaks and the recesses, knurled regions, bent teeth, as described in atleast one of the provisional patent applications 60/301,364, filed Jun.25, 2001, 60/327,814, filed Oct. 9, 2001, and 60/353,515, filed Feb. 1,2002, and as long as their depth does not exceed 0.2 mm, the mostpreferable configuration is one that comprises at most three rippleshaving a preferable depth not exceeding 0.2 mm, and more preferably notexceeding 0.1 mm. It is more preferable that the hindrance portioncomprises not more than two ripples, and even more preferable oneripple. Structures with one to three two-sided ripples 30 are shown inFIGS. 3B to 3D, respectively.

FIG. 2 illustrates a spring fastener 10 according to this invention,wherein the hindrance portion 29 comprises one two-sided ripple 30 andbent barbs 36.

The most efficient and effective case, however, according to thisinvention, is the use of only one single-sided ripple 30, as shown forexample in FIGS. 1 and 3A.

The operation of these embodiments is substantially the same as theoperation of the previous embodiments.

It is preferable that each ripple 30 is in the form of a depression, asbetter shown in FIG. 5. The depression has a deepest part Z, a frontside 32, a back side 34, and a width W1. The hindrance portion 29 has asurface E, and the depth D of each ripple 30 is defined as the distancebetween the surface E of the hindrance portion 29 and the deepest part Zof the respective ripple 30.

For better performance, the ripple width is larger than the depth of theripple, and preferably the ripple width is at least twice the size ofthe depth of the ripple. The ripple width is preferably in the range of0.1 to 0.5 mm and the ripple depth is in the range of 0.01 to 0.1 mm, asaforementioned.

In a preferred embodiment, the back side 34 of the ripple 30 issubstantially linear and has a slope S in the range of 15 to 30 degreeswith regard to the general plane of the surface E of the hindranceportion 29, and it is also preferable that the front side 32 has ahigher slope than the back side. The slope of the front side is measuredin the same manner as the slope of the back side. Thus, if the frontside 32 is substantially perpendicular to the surface E, the slope issubstantially 0 degrees, while if the front side 32 is substantiallyparallel to the plane of surface E and the continuation of the deepestpart Z, it is substantially 90 degrees.

It is, however, highly preferable that the back side 34 has the form ofa curvature with a gradually decreasing slope. For example, thegradually decreasing slope of back side 34 may have the shape of an arccorresponding to an angle A1, preferably in the range of 50-70 degrees,with a radius R, preferably in the range of 0.03-0.05 mm., as bettershown in FIG. 5A.

This configuration is of extreme importance in most occasions, becauseduring vibrations, the edges 51 of the slot 50 (FIG. 4C) slide smoothlyon the engagement regions 28 as well as the hindrance portions 29 duringoperation, and when they reach the back sides 34 of the single-sidedripples 30 (FIG. 5A), they continue sliding smoothly findingincreasingly higher resistance in a continuous manner, which eliminatesany rattling noises. Such rattling noises would be present in a casethat the edges 51 would hit abrupt obstacles or would suddenly jumpdown, even without hitting such obstacles.

The barbs are preferably selected from a group consisting essentiallyof:

-   -   first barbs 36 a being outer barbs, and second barbs 36 b being        inner barbs, as better shown in FIGS. 6 (blank before forming)        and 6A (side view);    -   first barbs 36 a being outside outer barbs, and second barbs 36        b being inside outer barbs, as better shown in FIG. 7 (blank        before forming); and    -   first barbs 36 a being inner barbs, and second barbs 36 b being        inner barbs, as better shown in FIG. 8 (blank before forming).

In operation, the barbs engage on the rib 46 of the first part 44, andwhen an adequate pulling force is applied on the firs part 44, thefastener remains on said first part 44, but is extracted from the slot50.

The spring fastener 10 may also comprise relief openings 42 a and 42 bin the vicinity of the bottom 16 of the spring fastener 10, as bettershown in FIG. 6 (blank before forming). These relief openings facilitatethe insertion of the fastener into the slot 50.

The spring fastener 10 may further comprise additional lower barbs 40 aand 40 b pointing inwardly and originating form the vicinity of thebottom portion 16 of the first side and the second side, respectively,of the fastener 10, as better shown in FIG. 9 (blank before forming).

In another embodiment, better illustrated in FIG. 10 (blank beforeforming), the first side of the spring fastener 10 has only one upperbarb 36 a and one lower barb 40 a, while the second side also has alsoonly one upper barb 36 b and only one lower barb 40 b, in a manner thatthe upper barb of one side faces the lower barb of the other side andvice versa.

The barbs 36 may have variable width along their length, as illustratedin for example in FIGS. 6-10, or they may have substantially the samewidth along their length as better shown in FIG. 11. Further, the frontpoints of the barbs 36 may be toothed, as illustrated in FIG. 12.

Regarding outside outer barbs 36, it is preferable that their frontpoints 38 are at a distance C from the second side 14 smaller than thethickness T of the material from which the spring fastener 10 is made,as better shown in FIG. 1A. This is to avoid interconnection of thefasteners, when said fasteners are stored in bulk.

It is preferable that the barbs are cut from their respective side, areflexible, and bent in the vicinity of their respective front end asdescribed for example in U.S. Pat. No. 6,279,207 B1, which isincorporated herein by reference, and more particularly in FIG. 1 ofsaid patent, with an angle of bent in the range of 5-25 degrees.

It is also preferable that the fastener 10 has a width W3 (FIG. 1A) inthe vicinity of the top portion 18 of the fastener 10, which is at least60%, and more preferably at least 70%, as wide as the slot width W2(FIG. 4C). Thus, it is preferable that the whole fastener complies withthis requirement, or at least a portion in the vicinity of the top. Thisis to avoid reversal of the direction and failure of the barbs 36, whenand if the rib 46 is forcefully pulled away from the second part 48(FIG. 4B).

With respect to the engagement regions 28, it is preferable that theseregions are at least partially wider than the rest of the respectiveengagement springs 20 (see for example FIG. 6).

The more barbs are present, or the more bent their front points are, thestronger the engagement of the rib 46 in the cavity 19. However, in manyoccasions it is desirable that this engagement is not so strong so as todestroy the integrity of the fastener or the rib, when an adequate forceis applied to separate the fastener 10 from the rib 46.

The spring fasteners 10 of the instant invention may have two engagementsprings 20 at the edges of each side instead of one engagement spring 20in substantially the middle portion of each side (see for Example FIG.10).

The spring fastener 10 of the instant invention may further comprise amolded elastic body 54 at least under the top portion 18 of said springfastener 10, as better shown in FIG. 13. Such arrangements are disclosedin U.S. Pat. No. 6,353,981 B1, which is incorporated herein byreference.

The operation of this embodiment is similar to the operation of thepreviously described embodiments with the difference that the elasticbody provides moderate sealing properties to the fastener when thefastener is inserted into the slot.

In another embodiment, the spring fastener of the instant invention mayfurther comprise:

an elastic body 54 comprised of at least a gasket 56, the gasket 56extending away from the closed cavity 19 in the vicinity of the topportion 18 of the fastener 10 and enclosing at least partially thecavity 19; and

a casing 58 surrounding at least partially the spring fastener under thetop portion 18, except at least the engagement region 28 of eachengagement spring 20, the casing 58 also at least partially surroundingthe cavity 19 and such portion of the elastic body 54 which at leastpartially encloses the cavity;

wherein the casing 58 has lower ultimate elongation, higher Shorehardness, and higher shear strength than the elastic body 54;

as better shown in FIG. 14.

The presence of lips 60 improves considerably the sealing properties ofthe elastic body.

Such arrangements are also disclosed in U.S. Pat. No. 6,381,811 B2,which is incorporated herein by reference.

The operation of this embodiment is similar to the operation of thepreviously described embodiments with the difference that thecombination of the elastic body 54 with the casing 58 provideoutstanding sealing properties to the fastener 10 when the fastener 10is inserted into the slot 50, and the casing itself facilitates theinsertion of the fastener 10 into the slot 50.

According to the present invention, any embodiments of fastenersdescribed above and their equivalents may be used in any assembly inwhich the first part and the second part are connected with thefastener, as well as in any vehicle comprising such an assembly or sucha fastener or its equivalents.

It should also be understood that the miscellaneous embodiments andfeatures of the instant invention may be used in any combination or bythemselves in other articles or devices, where they may be needed.

Examples of embodiments demonstrating the operation of the instantinvention, have been given for illustration purposes only, and shouldnot be construed as restricting the scope or limits of this invention inany way.

1. An assembly comprising: a spring fastener comprising a first side anda second side opposite the first side, the first side connected to thesecond side thereby forming a U-shaped structure having a cavity betweenthe first side and the second side, a bottom portion wherein the firstside and the second side are connected, and a top portion, the firstside comprising first barbs having first front ends, and a firstengagement spring, the first engagement spring connected to the firstside in the vicinity of the bottom portion, the second side comprisingsecond barbs second front ends, and a second engagement spring, thesecond engagement spring connected to the second side in the vicinity ofthe bottom portion, each of the first and second engagement springshaving a recess and a free end in the vicinity of the top portion, eachspring also comprising a peak and an engagement region with a hindranceportion between the recess and the peak, the hindrance portioncomprising one structure selected from ripple, side rib, upward solidbent extension parallel to the peak and the recess, knurled region, bentteeth, each having a depth, and a combination thereof; a first partcomprising a rib inserted into the cavity of the spring fastener andengaged to the first and second barbs; and a second part comprising aslot, the slot having a width and edges, the fastener being disposed inthe slot in a manner that the edges of said slot are engaged to theengagement regions of the spring fastener; with the requirement that bypulling the rib, the fastener is extracted from the slot without damageto the fastener, and with a higher force than a force required in theabsence of the hindrance portion.
 2. An assembly as defined in claim 1,wherein the depth of the ripple, the side rib, the upward solid bentextension which is parallel to the peak, the knurled region, and thebent teeth is smaller than 0.2 mm.
 3. An assembly as defined in claim 1,wherein each ripple has the form of a depression, the depression havinga deepest part, a front side, a back side and a width, and the hindranceportion has a surface, comprises not more than three ripples, andwherein the depth of each ripple is the distance between the surface ofthe hindrance portion and the deepest part of the respective ripple. 4.An assembly as defined in claim 3, wherein hindrance portion comprisesnot more than two ripples.
 5. An assembly as defined in claim 4, whereinthe hindrance portion comprises only one ripple.
 6. An assembly asdefined in claim 5, wherein the ripple width is larger than the depth ofthe ripple.
 7. An assembly as defined in claim 6, wherein the ripplewidth is at least twice the size of the depth of the ripple.
 8. Anassembly as defined in claim 6, wherein the ripple width is in the rangeof 0.1 to 0.5 mm and the ripple depth is in the range of 0.01 to 0.1 mm.9. An assembly as defined in claim 3, wherein the back side has a slopein the range of 15 to 30 degrees with regard to the general plane of thehindrance portion.
 10. An assembly as defined in claim 3, wherein thefront side has a higher slope than the back side.
 11. An assembly asdefined in claim 5, wherein the ripple has only a back side,substantially lacking a front side.
 12. An assembly as defined in claim11, wherein the back side has the form of a curvature with a graduallydecreasing slope.
 13. An assembly as defined in claim 12, wherein thegradually decreasing slope has the shape of an arc in the range of 50-70degrees with a radius in the range of 0.03-0.05 mm.
 14. An assembly asdefined in claim 1, wherein the barbs are selected from a groupconsisting essentially of: first barbs being outer barbs and secondbarbs being inner barbs; first barbs being outside outer barbs andsecond barbs being inside outer barbs; and first barbs being inner barbsand second barbs being inner barbs.
 15. An assembly as defined in claim3, wherein the barbs are selected from a group consisting essentiallyof: first barbs being outer barbs and second barbs being inner barbs;first barbs being outside outer barbs and second barbs being insideouter barbs; and first barbs being inner barbs and second barbs beinginner barbs.
 16. An assembly as defined in claim 11, wherein the barbsare selected from a group consisting essentially of: first barbs beingouter barbs and second barbs being inner barbs; first barbs beingoutside outer barbs and second barbs being inside outer barbs; and firstbarbs being inner barbs and second barbs being inner barbs.
 17. Anassembly as defined in claim 12, wherein the barbs are selected from agroup consisting essentially of: first barbs being outer barbs andsecond barbs being inner barbs; first barbs being outside outer barbsand second barbs being inside outer barbs; and first barbs being innerbarbs and second barbs being inner barbs.
 18. An assembly as defined inclaim 14, wherein at least one barb is cut from its respective side,flexible, and bent at its respective front end.
 19. An assembly asdefined in claim 15, wherein at least one barb is cut from itsrespective side, flexible, and bent at its respective front end.
 20. Anassembly as defined in claim 16, wherein at least one barb is cut fromits respective side, flexible, and bent at its respective front end. 21.An assembly as defined in claim 17, wherein at least one barb is cutfrom its respective side, flexible, and bent at its respective frontend.
 22. An assembly as defined in claim 14, wherein the material fromwhich the spring fastener has a thickness, and the front points of theoutside outer barbs are at a distance from the second side smaller thanthe thickness of said material.
 23. An assembly as defined in claim 17,wherein the material from which the spring fastener has a thickness, andthe front points of the outside outer barbs are at a distance from thesecond side smaller than the thickness of said material.
 24. An assemblyas defined in claim 21, wherein the material from which the springfastener has a thickness, and the front points of the outside outerbarbs are at a distance from the second side smaller than the thicknessof said material.
 25. An assembly as defined in claim 1, wherein thefastener has a width in the vicinity of the top portion of the fastenerwhich is at least 60% as wide as the slot width.
 26. An assembly asdefined in claim 1, wherein the engagement region is at least partiallywider than the rest of the engagement spring.
 27. An assembly as definedin claim 3, wherein the engagement region is at least partially widerthan the rest of the engagement spring.
 28. An assembly as defined inclaim 11, wherein the engagement region is at least partially wider thanthe rest of the engagement spring.
 29. An assembly as defined in claim12, wherein the engagement region is at least partially wider than therest of the engagement spring.
 30. An assembly as defined in claim 1,wherein the spring fastener further comprises additional lower barbspointing inwardly and originating form the vicinity of the bottomportions of the first side and the second side of the fastener.
 31. Anassembly as defined in claim 1, wherein each side of the spring fastenerhas only one upper barb and one lower barb, the upper barb of one sidefacing the lower barb of the other side and vice versa.
 32. An assemblyas defined in claim 1, wherein the spring fastener further comprises arelief opening in the vicinity of the bottom of the spring fastener. 33.An assembly as defined in claim 1, wherein a force to insert the rib ofthe first part into the cavity of the spring fastener is less than 40lbs; a force to insert the spring fastener into the slot of the secondpart is less that 30 lbs; and a force to extract the spring fastenerfrom the slot is in the range of 30-100 lbs.
 34. An assembly as definedin claim 1, wherein the fastener further comprises a molded elastic bodyunder the top portion of said spring fastener.
 35. An assembly asdefined in claim 1, wherein the fastener further comprises: an elasticbody comprised of at least a gasket, the gasket extending away from theclosed cavity in the vicinity of the top portion of the fastener andenclosing at least partially the cavity; a casing surrounding at leastpartially the spring fastener under the top portion, except at least theengagement section of each engagement spring, the casing also at leastpartially surrounding the cavity and such portion of the elastic bodywhich at least partially encloses the cavity; wherein the casing haslower ultimate elongation, higher Shore hardness, and higher shearstrength than the elastic body.